influxdb/http/flux_lang.go

151 lines
3.8 KiB
Go

package http
import (
"encoding/json"
"net/http"
"github.com/influxdata/platform/query/complete"
"github.com/influxdata/platform/query/parser"
"github.com/julienschmidt/httprouter"
)
// FluxLangHandler represents an HTTP API handler for buckets.
type FluxLangHandler struct {
*httprouter.Router
}
type astRequest struct {
Body string `json:"body"`
}
// NewFluxLangHandler returns a new instance of FluxLangHandler.
func NewFluxLangHandler() *FluxLangHandler {
h := &FluxLangHandler{
Router: httprouter.New(),
}
h.HandlerFunc("GET", "/v2/flux", h.getFlux)
h.HandlerFunc("POST", "/v2/flux/ast", h.postFluxAST)
h.HandlerFunc("GET", "/v2/flux/suggestions", h.getFluxSuggestions)
h.HandlerFunc("GET", "/v2/flux/suggestions/:name", h.getFluxSuggestion)
return h
}
// fluxParams contain flux funciton parameters as defined by the semantic graph
type fluxParams map[string]string
// suggestionsResponse provides a list of available Flux functions
type suggestionsResponse struct {
Functions []suggestionResponse `json:"funcs"`
}
// suggestionResponse provides the parameters available for a given Flux function
type suggestionResponse struct {
Name string `json:"name"`
Params fluxParams `json:"params"`
}
type fluxLinks struct {
Self string `json:"self"` // Self link mapping to this resource
Suggestions string `json:"suggestions"` // URL for flux builder function suggestions
AST string `json:"ast"` // URL for flux ast
}
type fluxResponse struct {
Links fluxLinks `json:"links"`
}
var getFluxResponse = fluxResponse{
Links: fluxLinks{
Self: "/v2/flux",
AST: "/v2/flux/ast",
Suggestions: "/v2/flux/suggestions",
},
}
// getFlux returns a list of links for the Flux API
func (h *FluxLangHandler) getFlux(w http.ResponseWriter, r *http.Request) {
ctx := r.Context()
if err := encodeResponse(ctx, w, http.StatusOK, getFluxResponse); err != nil {
EncodeError(ctx, err, w)
return
}
}
// postFluxAST returns a flux AST for provided flux string
func (h *FluxLangHandler) postFluxAST(w http.ResponseWriter, r *http.Request) {
var request astRequest
ctx := r.Context()
err := json.NewDecoder(r.Body).Decode(&request)
if err != nil {
EncodeError(ctx, err, w)
return
}
ast, err := parser.NewAST(request.Body)
if err != nil {
EncodeError(ctx, err, w)
return
}
if err := encodeResponse(ctx, w, http.StatusOK, ast); err != nil {
EncodeError(ctx, err, w)
return
}
}
// getFluxSuggestions returns a list of available Flux functions for the Flux Builder
func (h *FluxLangHandler) getFluxSuggestions(w http.ResponseWriter, r *http.Request) {
ctx := r.Context()
completer := complete.DefaultCompleter()
names := completer.FunctionNames()
var functions []suggestionResponse
for _, name := range names {
suggestion, err := completer.FunctionSuggestion(name)
if err != nil {
EncodeError(ctx, err, w)
return
}
filteredParams := make(fluxParams)
for key, value := range suggestion.Params {
if key == "table" {
continue
}
filteredParams[key] = value
}
functions = append(functions, suggestionResponse{
Name: name,
Params: filteredParams,
})
}
res := suggestionsResponse{Functions: functions}
if err := encodeResponse(ctx, w, http.StatusOK, res); err != nil {
EncodeError(ctx, err, w)
return
}
}
// getFluxSuggestion returns the function parameters for the requested function
func (h *FluxLangHandler) getFluxSuggestion(w http.ResponseWriter, r *http.Request) {
ctx := r.Context()
name := httprouter.ParamsFromContext(ctx).ByName("name")
completer := complete.DefaultCompleter()
suggestion, err := completer.FunctionSuggestion(name)
if err != nil {
EncodeError(ctx, err, w)
return
}
res := suggestionResponse{Name: name, Params: suggestion.Params}
if err := encodeResponse(ctx, w, http.StatusOK, res); err != nil {
EncodeError(ctx, err, w)
return
}
}